Quantitative Analysis of Interdental Gingiva in Patients With Chronic Periodontitis and Transforming Growth Factor-β1 29C/T Gene Polymorphisms

Background: The association of transforming growth factor (TGF)-beta 1 29C/T gene polymorphisms with level of tissue breakdown and periodontal disease progression is not clear. In this study, quantitative parameters of interdental papilla are investigated in patients with chronic periodontitis (CP) and TGF-beta 1 29C/T gene polymorphisms. Methods: Sixty gingiva samples were included. After determination of TGF-beta 1 29C/T gene polymorphisms using tetra-primer amplification refractory mutation system/polymerase chain reaction (T-ARMS-PCR), 15 gingival tissue samples from patients with CP in each genotype (TT, TC, and CC) were considered as case groups. Fifteen control samples were also collected from healthy individuals. After tissue processing, interdental gingiva tissues were exhaustively sectioned into 4-mu m-thick sections. Ten to 13 sections were sampled by systematic uniform random sampling and stained with Masson trichrome, and the volume density (V-v) of the gingival components was estimated using Cavalieri estimation. Results: Statistically significant differences were found in V-v of epithelium, connective tissue, collagenous and non-collagenous matrix, and blood vessels between control and CP groups (P < 0.0001). There was a corresponding decrease in the collagenous matrix V-v in patients with the TT genotype compared with those with CT and CC genotypes. Collagenous matrix and blood vessel V-v values were statistically correlated with the number of T alleles (r = -0.74, r(2) = 54.8%, P = 0.0001 and r = 0.84, r(2) = 70.6%, P = 0.0001, respectively). Conclusion: This study shows that there is a strong association between TGF-beta 1 29C/T gene polymorphisms and quantitative parameters of interdental papilla in patients with CP.